A Project Loon balloon crossed the WA coast near Cervantes this evening, tracking east-northeast at an altitude of 19km with a callsign of HBAL221.

https://en.wikipedia.org/wiki/Project_Loon wrote:Project Loon is a research and development project being developed by X (formerly Google X) with the mission of providing Internet access to rural and remote areas. The project uses high-altitude balloons placed in the stratosphere at an altitude of about 18 km (11 mi) to create an aerial wireless network with up to 4G-LTE speeds.

It's definitely an interesting concept. If only more would get blown in our direction so we could see how they group together.

Whilst I don't know how many balloons will be required for a given area of coverage, their ability to change altitude like a traditional hot air balloon allows them to have some choice over wind direction. This has proven successful for disaster relief, most recently for Puerto Rico after it was struck by Hurricane Maria.

But as X experimented with its balloons, the company realized that it could actually use wind to steer them north, south, east, and west. The balloons have on-board pumps that allow them to move up and down.

“From our millions of kilometers of test flights, we’ve been able to develop sophisticated models that allow us to more accurately predict the wind patterns at different altitudes,” a Project Loon post said in 2016. “Using this data, our software algorithms are able to determine which altitude has a wind pattern that gives us the best chance of keeping our balloons close to the areas where we want them.”

The company simulates 30 million kilometers of potential navigation daily to better understand how jet streams and weather patterns will impact balloon routes. Eventually, the team settled on a path that launches from Winnemucca, Nevada, and travels south. To date, balloons are still being launched on this trajectory, and as many as five to seven can be canvassing the island at a time.